Aquaponics USA

Aquaponics Fish


Tilapia Facts:

The Tilapia is a tropical fish whose native home is Africa and the Nile River Basin in lower Egypt. They are perhaps the oldest farmed fish on the planet as there are documented accounts of them having been farmed as far back as ancient Egypt. One of the oldest accounts of Tilapia farming is a bas-relief that was found in a 4,000 year old Egyptian tomb showing Tilapia held in ponds. The Tilapia was such an important food source for the Egyptians that it has it’s own hieroglyph. 

Currently, they are the most popular fish of Aquaponic farmers, and many Tilapia species are being farmed. The Nile Tilapia and the Mozambique are two of the favored species because they grow very fast while refraining from breeding until they are older. Due to this prolific farming of Tilapia, several hybrid species have been created as well.  It’s full pouty lips, (many women have paid a pretty penny for lips like this) are the doorway of the nursery for a mother Tilapia who scoops up the fertilized eggs she laid in the nest built by the male and carries them in her mouth for 4-8 days.  She continues to carry the newly hatched baby fish called “fry” for another 3-5 days. At this point the fry hang out in schools all rushing back to the safety of these prominent lips when danger approaches. As a Tilapia grower, you are gifted with the beauty of observing this natural cycle right in your Tank as adult female Tilapia spawn every 4-6 weeks.

Why Grow (culture) Tilapia?

Tilapia are tough fish--not to chew. In that regard, they’re as soft as butter. Rather, they’re rugged, resistant to disease and parasites and can tolerate lots of beginner learning-curve issues. They can handle a wide range of water quality and temperature challenges, and they can survive longer in a toxic water environment with low oxygen and/or high ammonia levels. Tilapia thrive in water temperatures between 60-80 degrees F preferring the 80 degree end of the scale, but they are usually raised in temperatures between 72-74 degrees F to better serve the plants. They are also easy to breed, and they grow to maturity faster than most other cultured fish.  In the best of environments, a Tilapia can grow to 2.5 lbs. in seven months. That’s the up-side.

Here’s the down-side.  Because they’re so easy to breed and spawn every 4-6 weeks, your system can quickly become overrun with the little schooling frys creating a negative impact on the ability of the more mature fish to grow. So you have to get a handle on breeding early and have a second tank available for your frys. Selling the frys can be a lucrative business in itself as they can be difficult to get in some areas. Tilapia are omnivores.   They eat both plants and organic materials. Although they do not eat other fish, their resilience and hardiness makes them dominant in the waterway; and they soon crowd out the native fish. This explains why the Tilapia has been outlawed in some communities. If you are considering culturing Tilapia, you need to check your local ordinances before doing so.

What Other Types Of Fish Can You Grow?

If you can’t or don’t wish to grow Tilapia, there are several other species of fish that you can culture including Trout, Largemouth Bass, Blue Gill, Catfish, Koi and Goldfish. In Australia where Aquaponics is more well known, they are growing fish that are native to that continent. They include Barramundi, Jade Perch, Silver Perch and Murray Cod. Here are some of the pros & cons that come with culturing these


This fish is much less tolerant to unfavorable water conditions than the Tilapia. It can be successfully grown in an Aquaponic system, but it requires a vigilant and patient grower to do so because it takes between 16-17 months to produce a table-ready fish and a lot can go wrong. They do not do well with less than delicate handling. Nor do they like bright light and cannot tolerate poor nutrition. They are one of the most sensitive fish to raise; and their water temperature and oxygen levels need to be monitored daily.  The young fingerlings need to be trained to feed on pellets.

As the household cat is to the lion, the domesticated Koi is to it’s often huge, wild counterpart, the Carp.  Koi are brightly colored, miniaturized Carp. They are considered to be ornamental fish rather than food fish even though they are quite tasty. Koi demonstrate a high tolerance to a variety of water conditions and can, therefore, be a good choice for an Aquaponic farmer. They can also be sold to individuals or pet stores for considerably more money than fish sold as food. However, if your goal is to become food independent, raising fish you want to eat is a better choice.

The trout is another temperamental fish to grow in an Aquaponic system. It’s very different from the Tilapia in that it’s a cold water fish and likes water temperatures that are much cooler than the tropical 70-75 degrees F of a Tilapia tank. Some growers who reside in colder climates, especially in the winter, will grow Trout during those months. But the cold water makes the selection of plants more limited as many plants prefer the more tropical water temperatures. Trout need pristine water conditions.

The catfish is a hardy fish that is resistant to both disease and parasites when living in quality-controlled water. But if oxygen and ammonia levels aren’t properly maintained, they will have difficulties. Like Tilapia, Catfish thrive in warm water and prefer a temperature of 80 degrees F. They are bottom dwellers, meaning they occupy only the bottom portion of the tank making for a low density fish crop if you raise them alone. Therefore, many farmers raise them with Blue Gill who use the upper portion of the tank and thrive in the same tropical conditions.

Like their first cousin, Koi, Goldfish are also miniaturized Carp. They are hardy and can be cultured right along with their Koi cousins.  Goldfish have a shorter dorsal fin base and a more forked tail than Koi. Like Koi, they can be sold for their ornamental value rather than their food value. However, if the horrors of food shortages actually do show up on American soil, and you can’t picture your dinner plate with a cute, little, fried goldfish laying on it, grow edible fish instead.

Oops! We’re not at all sure how this guy got in the line-up. No, you wouldn’t want to farm Angel Fish or any of their cohorts.  Can you imagine staring down at a lovely Angel Fish on your plate? But aren’t they beautiful.  We’ll save this space to talk about Fish Food in the near future.  In the meantime, sit back, relax and enjoy the fish parade.

Here’s An Interesting Discovery.

Angel Fish are related to Tilapia but not this guy. This is a salt water Angel fish. It’s the fresh water Angel Fish that is a relative of fresh water Tilapia. Both species are from the same family. It’s the the family Cichlidae in the order Perciformes. This is one of the largest vertebrate families with an estimated number of species ranging from 1,300 to 3,000 species and new species are still be discovered. Cichlids span a wide range of body sizes, from species as small as 2.5 centimeters (1.0 in) in length to much larger species approaching 1 metre (3 ft) in length. Many cichlids, particularly the Tilapias, are important food fish, while others are valued game fish (eg. Cichla species). Many species, including the Angel fish, Oscars, and Discus, are also highly valued in the aquarium trade.

Many fish lovers have also taken to raising Tilapia as their tropical aquarium fish because they find them to be highly intelligent, aggressive and interesting to observe in their see-through tanks. If you’re a vegan who is not interested in eating fish, Tilapia would still be an excellent choice in your Family and STEM Food Growing System tank.

A Little History of Aquaponics.

Aquaponic farmers the world over are experimenting with several species in their search for the tastiest, hardiest and most economical fish to harvest. And for the time being, the Tilapia has risen to the top in that contest. The University of the Virgin Islands at St. Croix is presently offering a one week course in Aquaponics featuring the production of both Red and Nile Tilapia along with the cultivation of vegetables, herbs and ornamental flowers. The UVI’s Agricultural Experiment Station was originally led by Dr. James Rakocy. He and his Department were forerunners in Aquaponic technology and research since the early eighties. Dr. Rakocy retired from the University in 2010 and  became a founder of The Aquaponics Doctors, an Aquaponics Consulting and Project Development Company. So technically, the United States has contributed a lot to the growth and development of this Agri-Tech that can quite literally save people from starvation. However, perhaps because of the off-mainland location of UVI, until recently, the Aquaponic story has been relegated to the backwaters as far as most Americans were concerned. It has only been in the last decade that Aquaponics has come into the mainstream (pun intended).

What About Governmental Regulations?

There are several different kinds of Tilapia species, and if you're planning to raise them in your AP System, it's important to check with your State Fish and Game Department to see which species are legal to raise in your area. For example, in California, only O. Mosambique Tilapia and O. Hornorum are legal to raise. The “O” stands for Oreochromis. Oreochromis is a large class called “genus” of tillipine cichlids which are fish endemic to Africa. Members of this genus, as well as those of the genera Sarotherodon, share the common name "tilapia". So the first thing we learned about raising tilapia is you have to do your homework and determine which (if any) species is legal in your state and /or county.

It seems there are a lot of politics around this fish, which is a non-native fish everywhere except Africa, its home of origin. The Aquaponic farmers in most of Australia are bemoaning the fact that no tilapia are legal there either (not even one species).

The Mosambique has been in California for so long, it’s now considered indigenous (at least south of the Tehachapi Mountains). Significant worldwide distribution of tilapia, primarily Oreochromis Mossambicus, occurred during the 1940s and 1950s. So by the mid 1960’s, when hydrilla weed started clogging California irrigation channels, it wasn’t a big stretch to bring in Mosambiques to abate the invasion. They did their job and slowly found their way to the Salton Sea. There they thrived in the saline waters as this hardy species can be raised in both fresh and salt water. In the fish world, they call this trait “euryhaline.” Fish that are exclusively limited to salt or fresh water are called “stenohaline.” At this point in time, however, only the toughest euryhaline Mosambique can survive in the over saline Salton Sea.

In general tilapia are being farmed in large numbers around the world ranking sixth among all farmed fish. They are very important for their food value both to humans and other carnivorous fish like salmon.  When one genus of fish is fed to another, the one being eaten is called “forage food;” and tilapia rank high in that category.  But they have also become known for what they can contribute alive like their ability to control aquatic weeds, algae and clean up waste-water treatment run off as they are omnivores and can survive on just about anything including waste.

Although tilapia have had a bad wrap and are still banned in several states in the US and other countries, they are slowly demonstrating their importance as both a high protein food source as well as in aquatic maintenance control. As food shortages grow around the world, and aquaponics becomes a household word in America, we see a time when these bans and restrictions on tilapia will of necessity be reevaluated and even lifted.

How Do Female Mosambique Produce Mostly Males?

Because mixed populations of tilapia, male and female, mate with great abundance, an aquatic farmer can loose control of his situation quite quickly and end up with too many youngsters who take up too much room in the AP System whether it be a pond or a tank causing slow, stunted growth among the adults.

One of the solutions for this problem is hybridizing two different species within the genus to create females that produce mostly males. This is done by crossing a male O. Hornorum tilapia with a female O. Mossambicus tilapia. The O. Mossambicus has XX chromosomes and the O. Hornorum male, ZZ chromosomes. Because the Z chromosome is dominant over the X, the resulting offspring are all ZX, which is male.

The plus side of that arrangement is you no longer need to worry about over population in your AP system. The downside is you no longer have a pure strain of O. Mossambicus tilapia or O. Hornorum tilapia. You have a hybrid strain. We have never needed to resort to this plan as there is a built-in fail safe when you leave the fry in the Tank. The teen tilapia need lots of proteing and will eat the fry so it's the quickest and most intelligent fry that survive.

What Are Some Of The Other Popular Tilapia Species?

Two of the tilapia species that kept coming up as we searched for our fish were the Nile and the Blue Tilapia.

The scientific name for the Nile tilapia is Oreochromis Niloticus. Whereas the O. Mossambicus came to the US in the 40’s and 50’s, the Nile tilapia didn’t come on the scene until 1974 when it was introduced to the US from Brazil. By 1978, the Nile tilapia arrived in China, and China soon became the world’s tilapia farming nation producing more than half of the world’s tilapia production from 1992 to present with mostly Nile tilapia. One of the advantages to raising Nile tilapia over Mosambiques is their ability to withstand cooler water temperatures. Another is their delayed sexual maturity coming into their breeding cycle at 5 or 6 months of age instead of 2 to 3 months.

The scientific name for the Blue tilapia is Oreochrmomis Aureus. They were introduced to the Gulf states in the 80‘s for weed and insect control. Blue Tilapia can be found in Florida, Alabama, and Texas, although Alabama winters often do not allow survival of most populations. It very well may be that in those states, the Blue Tilapia is now considered indigenous just like the Mosambiques in parts of California.

For aquaponics farmers, the Blue Tilapia is the most desirable of the genus precisely because it can survive in much cooler water than the other species.  If you read our Water page, you know the plants like the water cooler than the tilapia like it so you need to come to a mid-range between the two at around 72-74 degrees F. For Blue Tilapia that’s just fine. In fact, they can survive in temperatures all the way down to 48 degrees F although they will not grow fast or thrive at that very cold temperature.

Among those in the know, the Blue Tilapia is considered to be the best tasting of all of the Tilapia species. It yields very white, semi-firm fillets and has a great mild taste.  If Blue Tilapia are legal in your state, these are the fish to put in your aquaponics tanks, and you can get them right here on our Aquaponics Tilapia  For Sale Page. Click the Link or the image below to go there.

Mating Habits of Tilapia.

Tilapia come into sexual maturity at about eleven weeks old, which is several months before they are fully grown out (1 lb. or so). Once they reach sexual maturity, they spawn about every five to six weeks so each female can produce 200 to 300 mixed sex fry at each spawn. That’s a lot of fish. These are natural, sexually active fish so raising them means taking responsibility for their offspring; and, of course, you want offspring because that's what makes your system sustainable.

It has been our experience that overbreeding in a single tank system has not really been a problem because the juviniles in the tank are carnivores that need a lot of protein and they eat as many fry as they can find. In our first Greenhouse design, we had two, two-tank Family & STEM Growing Systems and one single tank Family & STEM Growing System set up in our 28' Greenhouse. The tanks were under the Grow Beds, which made for cumbersome fish husbandry. We really couldn't see what was going on in the tanks and were completely surprised when we saw fry in one of them. We have changed that design and don't recommend building space saving systems with tanks under Grow Beds due to this problem. Invariably, some of the fry manage to elude their hungry brothers and sisters and survive to repopulate your tank.

How Female Tilapia Brood Their Young.

Female O. Mossambicus are Mouth Brooders, which means they carry their eggs in their mouths to make sure they get lots of oxygen as the water swooshes through her mouth. Even the little fry spend a lot of time inside their mother’s mouth. Watch this amazing Video of a female Mossambicus with her fry.

What Are Sex Reversed Fish?

Because many large-scale fish farmers don’t want to deal with the breeding brooding issue, several ways have been devised to skirt this issue. I’ve already discussed the hybrid method above. Another very benign way to control breeding is to separate the sexes by hand called “hand sexing.”

But starting way back in the late seventies, when it became obvious tilapia were not going to perform well as a food source fish because of their prolific breeding that was causing poor performance in closed captive situations due to over-crowding, marine biologists started exploring the various methods of sex-reversal.

Sex-reversal is exactly what it says, a way to turn a potential female fry tilapia into a male through the use of testosterone. Because recently hatched tilapia fry do not have developed gonads it is possible to intervene at this early point in the life history and direct gonadal development to produce monosex populations. Steroids given in their food during the gonadal development period can control the phenotype overriding the expression of the genotypically determined sex. This process is commonly referred to as sex reversal.

Methyl-testosterone is the most commonly used androgen to direct the sex of tilapia. Androgen is the generic term for any natural or synthetic compound, usually a steroid hormone, that stimulates or controls the development and maintenance of masculine characteristics. Various protocols regarding dose rate and treatment duration have been evaluated. All depend on hormonal treatment with sexually undifferentiated fry. Other, rather bizarre sounding experiments to replace the methyl-testosterone with a natural form of testosterone have been tried with varying results. For example frozen bull testes added to the fry food did not work to create mostly male tilapia; but Haylor and Pascual (1991) reported successful tilapia sex reversal using ram testes as a source of dietary testosterone. The common method used today is a methyl-testosterone additive in the food. The upside is tilapia have become the sixth most popular farmed fish in the world. The downside is the widespread use of large quantities of sex reversal hormone in hatcheries may pose a health risk to workers (Mair, 1997) and there is little information on the fate of the hormone in the effluent and ground water.

Is the use of methyltestosterone safe for tilapia consumers? The standard answer is this: “Studies have shown that 5 days from withdrawal of the hormone feed, the levels of the male sex hormone in the treated fish return to normal indicating that no residues are present. With several months from the time of withdrawal of hormone feed to the time of consumption of the treated fish, consumers are assured that the fish are absolutely safe for eating.” We haven’t seen those studies nor do we know who’s conducting them. We do know that Whole Foods began banning testosterone in fish several years ago, searching the world to find fish farms that did not use the hormone. They even had to stop selling tilapia for a while before working out arrangements with farms in Ecuador and Costa Rica. Carrie Brownstein, the person who develops standards to guide seafood purchasing for the Whole Foods Chain throughout the U.S. said this, "We decided not to allow the treatment of any fish that are ultimately going into our seafood cases. We don't believe that the hormone treated fish really meet the expectations that our customers have."

Pure Strain Tilapia are Kosher.

According to and the Jewish Orthodox Union, true pure strain tilapia are a clean Kosher fish.

One word of caution, unless you’re raising your own tilapia, a strict Kosher eater should make sure he can identify the fish he is eating by purchasing it from a reputable Kosher store or by visibly seeing the fish with it’s skin on in order to determine that species substitution has not taken place.

What To Feed Your Tilapia?

Tilapia are omnivores, and, therefore, have the ability to eat just about anything. They love worms, grubs and will also eat leaves from the plants you're growing in your Grow Beds.

We've had great luck raising worms in our Deep Media Grow Beds where they really thrive because a Grow Bed is a perfect environment for them. We raised your garden variety Earth Worms; but have heard that Red Wigglers are the ideal worm for AP Deep Media System Grow Beds. We are not raising worms in our Arizona Greenhouse because we prefer working in worm-free Grow Beds, but if you're interested in raising worms, check out this resource below.

Where To Purchase Worms?

If you're interested in purchasing worms, we have the perfect place for you to go to do that. It's called Uncle Jim's Worm Farm.

Click on the above Banner and head on over. Uncle Jim also sells Indoor Composters, Outdoor Composters, Worm Kits, Vermipods, Books, Supplies, Meal Worms, Heirloom Seeds, Organic Fertilizer and Organic Pest Control.

To Purchase High Quality Tilapia Food (with no terrestrial animal parts in it) go to our Tilapia Food page.

How Many Fish in a 120 Gallon Aquaponics USA Family and STEM Food Growing System Fish Tank?

The question of fish to water ratio is a little tricky to answer. We have an entire page on this subject in Aquaponics 101.

The fish produce waste, mostly in the form of ammonia. This must be converted into nitrates which the fish can tolerate in greater quantities. The conversion takes place in the bio-filter/grow beds in our Aquaponics USA Family and STEM Food Growing Systems.

The nitrates generated by this process then must be absorbed by the plants or the nitrates will eventually overwhelm the system and poison the fish. This requires plants of some size to be in the grow beds. The less fish poundage, the less plant mass is required. In addition, different types of plants of the same size absorb nitrates at different rates.

There are no hard numbers to answer this question,; but we can give you some ballpark numbers. If there is enough bio filter and enough biomass and a variety of plant types, then you can support one pound of fish for 2 gallons of water. On the conservative end of the scale, you can support one pound of fish for every 10 gallons of water.

For a two grow bed system fully grown out with plants, one pound of fish for every 3 gallons of water. These numbers are maximums. Best to be more conservative as the system will be more stable with less chance of losing fish. As a general rule, beginners should stay on the side of less density. You can always increase your density as you become more experienced. When dealing with AP Systems, it's always a balancing act.

We have worked out this ratio for our STEM Teaching & Food Growing Systems and included the right number of fish that are included in the STEM Package for your System. The cartoon Tilapia below would like to say a special Thank You to you for visiting our Fish Page.

We sell Pure Strain Blue Tilapia that are known to be cold water resistant and delicious. We also have Mosambiques, Hawaiian Golds, White Nile and Red Nile.  Just click here or on the fish to Go directly to our Live Tilapia For Sale Page. 

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This is a Tilapia as are the Fish below in the slideshow. This fish is quickly becoming one of the most popular eating fish in the US because of it’s mild taste and firm, porous texture which readily absorbs the flavors around it. In fact, Tilapia have become so popular they've taken on the erroneous title, "Chicken of the Sea"–erroneous because they are a fresh water fish. Tilapia also happens to be the easiest fish to grow in an Aquaponics System (especially for beginners).

Words Of Warning: If you decide to go the other than Tilapia route, you're on your own. Tilapia are the only fish we've grown so if you get in trouble, we won't be able to help.

Aquaponics FISH